Statement  of Purpose

¡°The world is wide open to challenges and there are a lot of things you will be able to do in this world. Your care for, and dedication to, Life Science will make this world more prosperous and worth living in.¡± Kary Mullis, the Nobel Prize winner for his design of PCR, made this remark at a symposium I participated in while in graduate school. It has had a great effect on my lifetime goal, which is to contribute to the curing of diseases and to the pursuit of understanding the mystery of life. Mullis stressed the idea that the ¡°mysterious phenomena of life¡± will be gradually revealed when we combine our many small efforts to study Life Science. In addition, he stated that the promise of prosperity and welfare for human beings could be attained by working together consistently on a wide variety of problems such as medicine, food, environment, and energy. 

    I intend to pursue my goals in the Life Sciences, investigating the ¡°mysterious phenomena of life¡± by researching cellular phenomena on the molecular level. In this pursuit, it is necessary to gain an in-depth theoretical education combined with practical experience and cutting-edge molecular research techniques. I am fully convinced that studying abroad with your creative research staff, fresher ideas, and more specialized education and research programs will allow my dreams to come true, and is the best way to maximize my potential. 

I first encountered the Life Sciences after entering university. Life Science basically aims at understanding the mysteries that underlie life and growth, seeking to help human life thrive by unveiling its cellular and molecular secrets. When my interest in the Life Sciences was first aroused, I tried to gain necessary background knowledge by taking courses such as biology, chemistry, physics, physical chemistry, and organic chemistry. I became familiar with basic experimental techniques and decided to enter graduate school to gain further knowledge and more diverse research skills. 

During graduate school I acquired more detailed biochemical and molecular biological knowledge. For 2 years, with the help of the Ministry of Agriculture and Forestry in Korea, I participated as a Research Assistant in a project called ¡°Isolation of an Environmental Stress-Resistant Gene from Plants, and Molecular Breeding of Environmental Stress-Resistant Plants¡±. Throughout the project I gained concrete knowledge of DNA replication, transcription, translation, and regulation based on genetic information transmittal systems. I also became experienced with the experimental techniques of molecular biology in relation to molecular breeding and gene cloning. 

In 2000, I obtained an M.S. degree. My thesis was: ¡°Purification and Characterization of 1-Aminocyclopropane-1-Carboxylate Synthase from Cucumis melo.¡± In this study, the 1.4kb ACC synthase cDNA from melon fruit was cloned, overexpressed in E. coli, and the expressed ACC synthase was purified. A number of technical problems needed to be overcome. The investigation of ACC synthase was hampered by the extremely low expression of active enzyme in E. coli and by its short half-life. Because this enzyme is very labile, a rapid and simple purification procedure was necessary. To solve the latter problem, I developed a purification method that combined affinity chromatography with gel filtration chromatography using a fusion vector system. This improved two-step purification protocol allowed rapid purification. However, low expression levels of active enzyme were still a problem. I thought that during expression in E. coli, ACC synthase might be folded more accurately at the optimal temperature of plant growth rather than at the higher temperature of E. coli growth. Thus, I incubated the E. coli at low growth temperature (25^oC). In this way, I finally obtained enough soluble protein to be purified successfully.

During this research I gained a wide variety of knowledge and experimental expertise, ranging from purification techniques of various proteins, to enzyme assays. These serve as a sturdy foundation for my future biochemical and molecular biological studies and research.

Based on my knowledge and experience, I would like to conduct research on intracellular signal transduction and apoptosis. I am convinced that one of the essential tasks of Life science is discovering the regulatory mechanisms of the entire cell in the chronological order of growth, differentiation, and death. It is natural that if the development and death of a cell deviates from the ordinary regulation process, it can bring about numerous diseases. For example, apoptosis is deeply involved in the development of cancer and immune system disorders, including AIDS, Alzheimer¡¯s disease and Parkinson¡¯s disease. Therefore, it is necessary to explore the regulatory mechanisms of cell growth and death in order to develop new therapies. In this regard, I have great interest in the signals that control cell death.

In the same context, I am quite interested in the immune system. Immunology provides the understanding of various disease processes, making new diagnostic and therapeutic approaches possible. Beyond that, it produces a wide range of information on how to trigger cell development as well as how one cell can stimulate and suppress another cell. This research will be useful in the treatment of autoimmune disease, transplantation, and CTL immunotherapy. I believe molecular immunology is one of the fields of Life Science that can allow human beings enjoy their prosperity. These goals require a wide range of knowledge and a variety of techniques that your school will enable me to cultivate.

I will not pursue my academic goals to gain prizes, credit, or wealth. Ever since Watson and Crick discovered the DNA double helix structure in 1953, Life Science has made rapid progress. This accumulation of knowledge will be going on until the secrets of life are discovered, and will, therefore, go on forever. As one of many researchers in the field of Life Science, my work can contribute to the pursuit of this knowledge and the cure of diseases.

I strongly believe I have the capability and potential to study and conduct research at your school. I would appreciate the chance to realize my goals. Thank you.  

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